All's Fair
by bananannabeth
Summary: Rather than all of the 7 being teenagers, what if Jason and Piper were in their 30s when chosen for the quest? Jason's lived his life taking responsibility for everyone around him, while Piper's spent hers running as far away from all responsibility as possible. And now they're meant to help teenagers save the world? Oh, this'll go well. / Collab with the incredible Lilianne Chase


**a.n.** this story is based in a universe created by **Lilianne Chase** (author of the amazing Hidden, you probably know her), where rather than all of the seven being teenagers, Jason and Piper were in their 30s when chosen for the quest. this au is fondly known as Adult!Jasper and you can read alllll about it on our tumblrs - she's **lililibird** and i'm **bananannabeth**. also in this au are Punk!Percy and Girly!Annabeth.

* * *

Jason didn't remember quests being this tiring. The fact that this one seemed to be taking so much out of him was not a good sign, no matter how he looked at it. Maybe they had always been this tiring, but over time the exhaustion had faded from his memory, leaving nothing but the faint recollection of exhilaration. He remembered being excited on quests when he was younger, but he didn't feel any excitement now. So either his memory was failing him, or he'd turned into a bitter old man. Maybe it was both. **  
**

He rubbed his bad knee, massaging the joint and trying to get it to stop aching, while eyeing the kids on the other side of the deck. Percy was talking to an enamoured audience of Annabeth, Leo, Frank and Hazel, smirking around every word, which no doubt meant that he was telling them all about how Jason had taken a hit to the knee and crumpled immediately, leaving him to finish the monsters off single handedly. If Jason hadn't been so furious with himself for leaving his weakness exposed, and if Percy hadn't been so damn smug about it, Jason might have been proud of the kid for his prowess. As it was, he just felt agitated. Percy's tale must have wrapped up, because Hazel slowly lowered her hands from her mouth and Annabeth threw herself into Percy's arms with an exuberant squeal, kissing him right on the lips, not caring about their audience.

Jason looked away, scowling. He tried to remember if he and Reyna had ever been that handsy when they were teenagers, but it seemed a silly comparison to make. They had been a different sort of couple, born out of fondness and practicality, whereas Percy and Annabeth were made of a burning passion, a magnetism that kept them constantly in each other's orbit. Jason had never felt that kind of white hot desire for anyone before, except maybe -

"Hey, soldier. I hear you took quite the hit. Is that why you're scowling like that?"

Jason lifted his gaze to see Piper standing there, red bra the same shade as her lipstick visible through her sheer black blouse. He swallowed and shook his head, keeping his eyes locked firmly on her own.

"No, that's not why I'm - Wait, you heard about that? Already?"

She shrugged and dropped down onto the box beside him. Her skirt rode up her thighs as she sat, but Jason recognised this as a calculated move and so stubbornly pretended not to notice.

"Word travels fast on the Argo," she said, looking past him to the kids. "You know how teenagers are with their gossip."

"Oh, like you're any better," Jason said, and then immediately regretted it. His cheeks flushed pink. "I'm sorry, Piper, I didn't -"

Her gaze had snapped back to him, multicoloured eyes wide and searching. For a second her expression was completely blank, and he felt sick to his stomach. But then the corner of her cherry red lips lifted in a familiar smirk, and she slowly shook her head, choppy hair swinging across her shoulders. "My, my, you are grumpy today. Your knee _and_ your ego must have taken quite the hit."

Jason grumbled something indistinct and Piper laughed, a light musical sound that was beautiful but also not quite real. Jason had only heard Piper's genuine laugh three times so far, but it was already one of his favourite sounds in the world. This tinkling little thing she offered him now paled in comparison, and his scowl deepened.

"Maybe questing is a young man's game," she said with cloying sweetness.

Jason turned to her. "We're here for a reason, Piper. These kids need us, and -"

"They seem to think they can take care of themselves all right." Her eyes flickered over his shoulder, and he followed her gaze to see Annabeth leading Percy by the hand down onto the lower level, leaving Leo, Frank and Hazel deep in discussion on the other side of the deck.

Jason rubbed his temples. "Look, maybe they can take care of themselves with the physical combat side of things, but they need someone to set an example, to lead -"

"You're stressed," Piper said, and he could feel her charmspeak washing over him instantly. It was only a small amount, but it was potent enough to make him feel a bit lightheaded. "You just need to take your mind off things. Find something to… distract you. A little bit of stress relief."

Her hand grazed lightly over his bad knee and up his thigh, getting awfully close to his belt buckle before he swatted her away.

"On the deck of the ship? Really? You're going to try that here?"

She shrugged one shoulder and withdrew her hand. There was no charmspeak in her voice when she said, "Excuse me for getting a little adventurous."

Gods, Jason was tired. He was tired of chasing fruitless leads on this quest, he was tired of babysitting, he was tired of being outmatched by a sixteen year old boy who wore jeans with holes in them, he was tired of constantly having to rebuke Piper's advances when all he wanted to do was accept them. He was tired of his morals always beating his baser desires.

But Jason Grace had trained himself to be the perfect soldier, and he wasn't about to throw decades of hard work away, not even for Piper McLean.

He stood, leaning heavily on his good knee, and dragged a hand down his face. The stubble along his jaw prickled against the skin of his palm. "You can't keep doing this, Piper. You know that I - that I'm not the type of person to just do that without any… without any emotional attachment."

"Lust is an emotion," she said quickly, but the words lacked her usual bite.

Sitting in front of him then, shielded from the view of everyone else, Jason thought that Piper looked tired, too. Not because there were bags under her eyes or anything - oh no, she was as stunning as ever, so beautiful that Jason found it hard to breathe around her - but because of the stoop of her shoulders, the drop of her bottom lip, her general air. In that moment, she didn't appear as polished as normal. Jason's heart twisted.

"Not the one that I'm looking for," he said, and with that he turned and limped away.

* * *

A few days passed. Tensions didn't really ease. They were on the brink of a big development, everyone could feel it. They were all on edge, and they all dealt with it in different ways, all equally frustrating to Jason - except for Piper's. Her way of coping with the stress was to pretend that she didn't care in the slightest, and it _infuriated_ Jason.

She spent her days lazing around the ship, collecting idle gossip and drinking her way through their wine supply. Occasionally Jason caught her with her dagger out, but she only seemed to use it as a mirror. She spent every meeting making snide remarks, laughing at the way she could so easily rile everyone up. Whenever Jason tried to reign her in, Piper just laughed and sauntered from the room without a glance back, leaving everyone fuming in her wake.

Most of the kids stayed out of her way. Frank and Hazel knew better than to provoke her, and she got along fine with Leo, so he wasn't at risk of being caught in her line of fire (ironic in many ways, not least of which was the fact that he was probably the only one out of the lot who'd be able to laugh off her insults). Annabeth didn't exactly mean to piss her off - most of the time, anyway - but their personalities just clashed.

Piper felt that Annabeth was too highly strung and too serious and too in love with Percy and too clever for her own good and too smug and too young and just _too much_. And Annabeth felt that Piper wasn't serious enough, wasn't experienced enough, wasn't prepared for the responsibility that came with a quest like this in any way, shape or form. Which lead to some impressive arguments.

Annabeth was leaning over the opposite side of the table to Jason, poring over the maps they'd spread out across its surface, trying to decide which course would be best to take. Everyone else had long since retired to their individual rooms, leaving just the two of them and Percy, whose lap Annabeth had only recently vacated. She seemed too agitated to remain seated, and as soon as she'd stood up Percy had leaned his head back, exposing the hollow of his throat and the hickey visible underneath his collar. Jason bit down a comment and tried to focus on Annabeth's pale pink, perfectly manicured nail tapping at a spot on the map.

She said, "But if we go through here, we risk an attack from -"

A voice from the doorway behind Jason cut her off. "Oh my gods, you're still looking at those stupid maps?"

Jason almost jumped out of his skin as Piper stepped into the room, barefoot for once. Without the clicking of her trademark heels, he hadn't heard her coming. She brushed her open palm along the small of his back and made him shiver as she sauntered around to the head of the table, looking at the three of them in turn. She was wearing a red silk negligee and nothing else, and Jason suddenly found the topographical lines of the map more fascinating than ever before.

Jason heard Percy clear his throat, but it was Annabeth who spoke, her words clipped at the edges. "Unlike some people, we're actually interested in completing this quest. So yes, we're still here, trying to figure out a way to get everyone home alive. Thanks for your help."

Piper clicked her tongue. "Gods, kid, it's way past your bedtime and your hot boyfriend's sitting there drooling over how short that dress is, would you go put him out of his misery and get out of my face?"

At first the only thing Jason processed from that entire sentence was the phrase _hot boyfriend_. But then he registered the rest of it, and realised that Piper had just started something bad.

He looked up just in time to see Annabeth straightening, hands tugging down the hem of her pristine white dress, which was modest in length compared to Piper's current attire. Percy slowly stood and looped an arm around his girlfriend's waist, tilting his head down to whisper something in her ear. Annabeth made a low noise at the back of her throat that sounded an awful lot like a growl, and Jason noticed a flush rising up her neck. He wasn't sure if it had been brought on by Piper's words or her proximity to Percy, but either way he hated it.

"Piper, please -" he began to say, but Annabeth spoke over the top of him.

" _I_ don't need to wear short dresses to get the attention of the guy I like, but thanks for the advice." Her gaze was ice cold and far more intimidating than the stare of a sixteen year old had any right to be.

Percy turned his head into her blonde curls, but Jason couldn't tell if he was whispering in her ear again or just stifling a laugh.

Piper's eyes flashed. Jason stood up perfectly straight, hands splayed in front of him, and tried to ignore the dread churning in his stomach. Annabeth was so tired, and Piper was so scared, even though neither of them would ever admit it, and there was no way this was going to end well.

"Oh, don't act all high and mighty," Piper said, words heavy with charmspeak. She flashed a perfect smile, but her eyes were narrowed dangerously. "Your little teenage love affair isn't anything to be jealous of. It's called hormones, honey."

Percy's head snapped up and his grip around Annabeth tightened, so that she was pressed right against his side. He was taller than Piper, and on the rare occasions Percy chose to stand up straight, such as now, he could be extremely intimidating. The two teens didn't look as though the charmspeak had had that much of an effect on them.

Jason moved around the table to stand with Piper, just in case.

"Careful," Percy said, carding his fingers through Annabeth's hair in a casual movement that was entirely at odds with the venomous way he was speaking to Piper. "Your bitterness is showing."

Piper stalked forward and Jason had to grab her arm to hold her back. She shot him a glare but he held his ground, staring at her until she stepped back. She shrugged out of his hold and gave him a look that meant he'd pay for that later, but right then he didn't care.

"Guys, come on," Jason said, voice calm and reasonable. "We're all stressed, we're all tired, why don't we just go get some rest?"

"Hey, I just came in here to collect my book and I was unfairly attacked, I don't think _I'm_ the one who has to get some rest," Piper said, fanning a hand across her chest in a gesture that somehow managed to be both innocent and alluring.

Jason rolled his eyes. He couldn't believe she was really going to prolong this.

"Oh, that's nice. I wasn't aware you could read," Annabeth snapped. She really must have been exhausted, because the petty insult was well below the wit she was capable of, but it did the trick.

Piper's innocent act fell away immediately. "Okay, you know what, daughter of Athena?" She managed to make the title sound like an insult. "You're not the only clever one on this gods forsaken ship. Excuse me for not being as tightly wound as you, but I figured that having one uptight bitch on board was more than enough."

Not surprisingly, it was Percy who snapped first, before even Annabeth could respond. Before Jason could stop him, he got in Piper's face, green eyes dark and hands clenched into fists at his sides.

"You know what, Piper? At first I was glad to have you on board, because I thought you might help balance out Jason the hardass. But now I realise that you might actually be worse than him, because at least he admits that he's a boring old man. Whereas you, you're clinging desperately onto any shred of youth you might have left, trying to act all carefree and fun and like your life hasn't gone to absolute shit. And you might have gotten away with that, back in your mansion with your parties and your one night stands. But you can't get away with it here. Here, what you do actually matters, and it's about damn time that you start acting your age and accept some responsibility for your shitty behaviour."

Piper opened her mouth to respond, but Percy wasn't quite done yet.

"It isn't our fault," he growled, "that you've been chosen for this quest, and you can either suck it up and deal with it and start contributing something, or you can throw yourself overboard for all I care."

It was harsh, but Jason couldn't say that he hadn't been waiting for this. He gripped Piper's arm again, just in case, but she didn't move.

For a few tense moments, everything in the room was absolutely still and silent.

And then Annabeth reached out for Percy's hand. She gently unclenched his fist and laced her fingers through his, pulling him back towards her. With every inch of space that came between him and Piper, Percy seemed to calm down. Annabeth put her lips against his ear and murmured something, voice soft, and Percy just nodded stiffly. He ran his spare hand roughly through his hair and spun away from Jason and Piper. Annabeth threw them one last look over her shoulder, expression inscrutable, before the two of them disappeared down the hallway, hand in hand.

Jason listened for the sound of Percy's bedroom door slamming shut before he exhaled. He hadn't realised he was still holding Piper's arm until she wrenched herself free from his grasp. He didn't know what to say to her, but he wanted to say something.

"Piper -" he began, but that was far as he got.

She pushed him back up against the table, eyes flashing furiously. Jason forgot that he was a trained soldier, an extremely powerful demigod who had faced far scarier enemies than Piper McLean. For a second, he genuinely thought she was going to try and hurt him.

Instead, she kissed him. It was rough and somewhat desperate, her lips pressed against his as her nails scratched along the back of his neck. She pressed herself against him, and when Jason gasped she took the opportunity to deepen the kiss. He curled his hands around her waist, holding her steady, feeling the beating of her heart against his chest. The kiss was heady with lust, a desire that had been building steadily since that first day at the Grand Canyon. Piper smelt like expensive perfume and tasted like even more expensive wine, and Jason could feel himself getting lost in the kiss. She tugged on the short strands of hair at the nape of his neck, forcing his head back slightly, and as they parted some of his sense slowly came back to him.

He lifted his hands from her waist to her shoulders and pushed her back slightly, just enough so that he could breathe again. Instantly, her face fell.

Jason shook his head and said quietly, "Not like this, Piper. Not when you're angry, you don't want it to happen like this."

"Don't," was all she said, the single word accompanied by a blood red nail pointed right at his nose. Jason imagined a thousand different endings to that sentence - _Don't tell me what I want, Don't pretend you know how I feel, Don't pretend you want this any less than I do._ But she didn't say anything more. Without another sound, she turned and stormed off.

Jason really regretted not going to bed when he'd had the chance.

He found her in the early hours of the morning, sitting on the deck and staring at the stars. In the dim light the planes of her face appeared sharper, and rather than their usual multicoloured hue her irises just looked black. She looked older and darker, somehow more solid than normal, even though she was almost all shadow. She didn't turn her head as he approached, but he saw her shoulders tense. He stopped a few feet away and considered what to say.

"Come to reprimand me, Mr Grace?" she said before he'd made up his mind, voice dull and listless.

"Why do you do that?" he asked without preamble.

She quickly glanced at him before looking away again. "Do what?"

"Deliberately piss people off? Deliberately push people away? Why can't you just contribute to the discussion? I know you're clever, Piper, I know you have ideas that could help us with this quest. Why don't you share them?"

She snorted. "What are you talking about, Jason? I'm just a daughter of Aphrodite, how do you expect me to contribute to strategies and war games?"

Jason clenched his hands into fists at his sides. Piper's tough exterior, the conceited one that said she thought she was better than everyone else, was hard enough to deal with - but this, this secondary layer of insecurities, of self-deprecation in its cruelest form, this was worse.

"Don't play dumb! Don't - don't do that. I'm trying to talk to you, to have a mature conversation -"

"Why does everything have to be mature with you? Why can't you just do things without overthinking it?" He caught the glint of her eyes as she rolled them, and he knew that they weren't talking about battle strategies anymore.

"Because actions have consequences, and I care -"

"Oh, you care? You _care_?" Piper got to her feet and stood opposite him, spine straight and chin lifted. "What do you care about Jason? Saving the world? Going home a hero? Reliving your glory days?"

His rebuttal stuck in his throat. He could feel charmspeak in her words but he didn't doubt they would have stunned him even without that power.

She continued on, flinging her arms out to the sides, "Because guess what! Those days are over. This is no longer your game, and nothing you do is ever going to make you the hero you once were. And the sooner you realise that the sooner you'll be able to -"

"I care about _you_ , Piper."

She stopped dead, all the wind taken from her sails. Her hands dropped to her sides and she stared at him in silence, features rendered vulnerable by genuine shock.

He sighed, a deep, bone-rattling sigh, and looked at her hopelessly. "I just wish you cared about yourself half as much I care about you."

When she still didn't respond, he just shook his head and walked away, leaving her speechless and alone in the night.

* * *

Neither of them brought it up again, but Piper got a bit better after that.

She stopped deliberately antagonising Annabeth quite so much, which immediately decreased the tension between her and Percy, which helped put everyone else somewhat at ease. She started actually contributing to their meetings, offering a valuable perspective on what their enemies would be expecting that none of the others had considered before.

She spent less time drinking wine and more time with Leo in the engine room, getting to know the inner workings of the ship and telling him wild stories about her past. Jason took a detour by there some days, stopping outside the door where they couldn't see him and listening to them talk. Piper consistently gave Leo terrible advice about how to get a girlfriend, but whenever the conversation drifted into darker territory, like what had happened to Leo's mum or how he was genuinely worried that no one was ever going to love him again, she gave her responses the thoughtful consideration they deserved; she was honest without being blunt, caring without being patronising.

"People already love you, Leo. You've got a whole ship full of people who love you right here."

The teenager scowled and wiped his grease covered hands on his apron. "You know that's not what I mean."

Piper sighed, and Jason leaned closer to the edge of the doorway to hear her better over the constant hum of the engine. "Look, romantic love isn't all it's cracked up to be."

"You're a daughter of Aphrodite, how can you say that?"

"I'm a daughter of Aphrodite who's only ever been in love once, a long, long time ago, and look how that turned out." There was a pause, but she didn't elaborate and Leo didn't press her to. When she next spoke her voice was about as low and serious as Jason had ever heard it. "It's not nice being vulnerable like that, Leo. Trusting your whole self to another person, giving them the power to break you? It's scary. Every time you let yourself fall in love with someone, you lose a piece of who you were before. You're changed forever, just through the simple act of loving them, even without them loving you back. And people try to tell you a relationship is about being equals, but it's not. One person always has more power than the other, and it's never fair."

"All's fair in love and war though, right?" Leo half-joked, trying to lighten the mood in a way that was painfully obvious.

There was a long silence, and Jason held his breath as he waited to hear what Piper would say. Just as he began to think that maybe he didn't want to know her response after all, he heard her sigh.

Her voice was soft and sad and not at all like the one she used around Jason when she said, "Maybe. But you can't be in love while you're in a war."

As quietly as he could, Jason turned and walked back the way he'd come, her words echoing in his ears.


End file.
